1903.] THE MUSCLES OF THE UNGULATA. 275 



that of the sartorius, while from its lower margin it gives off an 

 expansion to the inner side of the tendo Achillis which blends 

 with similar expansions of the biceps and semitendinosus to form 

 the sheath for that tendon. This sheath has already been dis- 

 cussed under the head of the semitendinosus. The muscle seems 

 so constant in the various families that it is needless to i-epeat 

 each individual record, especially as there are thirty-four of them 

 fairly evenly distributed over the order ; it will be sufficient to 

 point out that according to Murie (XXXII.) the muscle is absent 

 in the Giraffe, while Chauveau (II.) says that in the Camel its 

 origin is bifid, the anterior branch being the smaller. Meckel 

 (YII.), on the other hand, says that there are four heads to the 

 gracilis in the Camel, so that it is clear that further knowledge 

 is needed on this point. The nerve- supply in every animal we 

 dissected was the obturator. 



Muscles of the Anterior Femoral Region, 



Sartorius {Rio-tibialis). — ^The origin of this muscle is usually 

 not so high as the anterior superior spine of the ilium, more often 

 it comes from the iliac fascia covering the insertion of the psoas 

 parvus as well as from Poupart's ligament close by. In the Ox 

 (35, 36, 37), Sheep (41, 42, 46, 48), and Goat (50) it has another 

 origin from the pubis just internal to the femoral vessels, but the 

 two origins soon join so that the vessels pierce the conjoined 

 origin. The insertion is into the upper part of the tibia by 

 means of the fascia of the thigh ; sometimes the fleshy fibres 

 reach as far as, or even beyond, the knee, but more often they are 

 lost in the fascia lata or join the tendon of the gracilis before 

 the knee is reached. In the Perissodactyla the sartorius seems 

 rather better developed than in the rest of the Ungulata, at all 

 events it remains fleshy below the knee in the Horse (63), Tapir 

 (58, 59, 60, 61), and Rhinoceros (71). Sometimes the muscle is 

 absent, this was the case in Hyrax (74, 75) ; and we have no 

 doubt that what Meckel describes in this animal (78) as sartorius 

 is really tensor fasciae femoris. It was also absent in Anderson's 

 Elephant (79), and Cuvier and Laurillard (84) do not figure it, 

 though it is definitely described by Miall and Greenwood (81) as 

 well as by Paterson and Dun (85). On comparing this muscle in 

 the Ungulata with its condition in other orders, it will be seen 

 that it is better developed than in many of them, and may cover 

 in the femoral vessels, making a definite Hunter's canal. Its 

 nerve-supply in the Pig, Sheep, Duiker- bok, Harnessed Antelope, 

 and Elephant is the anterior crural, the special branch to it 

 passing over (superficial to) the femoi-al vessels a little below 

 Poupart's ligament. 



The Quadriceps extensor criiris has only a few points of special 

 interest so far as our observations go. The rectus, as is usual in 

 mammals, always has a reflected head, and often a straight head 

 too, though the two may be continuous and so only one is 

 described. "We have so far not met with a single ungulate in 



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